Stone fabrication positioning system

ABSTRACT

A stone cutting system effective for mechanically delineating defined datum points in a Cartesian coordinate system by positioning at least one datum point defining means per coordinate comprising a combination blocking and clamping device, a table of a computer numerically controlled (CNC) stoneworking machine, a locating means positioned on the table, the blocking and clamping device being in the form of a parallelepiped including a bottom surface having a plurality of apertures adapted to enable positioning about the locating means, a top surface having a first blocking edge and a second clamping edge, including at least one means for clamping a workpiece within said top surface second clamping edge, a left side surface, a right side surface, a front surface, a rear surface, and at least one means for fixation of said device on said table.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 60/735,299, filed Nov. 10, 2005, the contents of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to stone cutting and, more particularly, to an automated stone cutting system and method for cutting and shaping various stone materials, such as marble, granite, and limestone, in any number of preprogramed shapes so as to eliminate the need for manual stone cutting operations.

BACKGROUND OF THE INVENTION

It has recently become fashionable to use marble, granite, stone and glass in interior design. This requires that manufacturers of stone cutting and machining equipment pay particular attention to systems for making work surfaces, especially for bathrooms and kitchens, as well as to any interior design work using stone material.

Templates made from wood, PVC, or other materials for guiding cutting machines along a defined path on slabs of stone have long been known. The larger companies in the industry utilize large computer numerically controlled (CNC) machines which have disadvantages of increasing costs and machining times when they are used on a non-industrial scale, for short runs, or on individual pieces because of the high labor and programming costs to start each run.

Some smaller companies employ small or medium sized equipment of the manual or semi-automatic type. These have the disadvantages of imperfections in the cutting and machining owing to the difficulty of clamping the template, to be followed, onto the slab of stone.

Another type of machine is a bench machine which utilizes a pivoting arm. In these machines it is known to mount a template on the top of the surface to be cut or machined. The template is drilled and fitted in place with bolts connected to a template-holding frame and the copying action is done by means of a long shaft or tracer which carries a follower wheel which during cutting advances into contact with the template and determines when the cutting is to end. This system has the disadvantage of flexing of the arm which carries the follower wheel which leads to undesirable undulations in the outline of the material being cut.

DESCRIPTION OF THE PRIOR ART

Other systems, normally employed with cutting machines, position the template against the slab to be cut, either above it or below it according to need, and held a suitable distance away from it by distance pieces interposed between the slab and the template, or by other means for raising the slab and template off the work surface. The whole assembly is then immobilized by somewhat insecure systems such as clamps or the like, which cause inevitable loss of time and practical difficulties of cutting since the machine is unable to work in the areas in which the clamps are positioned since the clamps have to be repeatedly moved. Also the wooden or PVC templates tend to bend in the areas on which the clamps are applied.

Also current systems which utilize CNC cutters employ a CAD-CAM program to operate the cutter. The operator must digitize each individual piece of stone and then program the production into the machine's CAD-CAM system before running the program. This results in a substantial amount of set-up time for each stone that is being cut.

U.S. Pat. No. 6,068,547 issued to Lupi discloses a system for the machining of slabs of stone, glass and the like, using templates. The system comprises a plurality of mechanically adjustable pneumatically operating distance pieces or supporting blocks. Each distance piece or supporting block is adjustable for height by means of a screw and nut arrangement. They are also provided with suction seals on their end surfaces to support the slab, on an annular step to hold the machining template, and on the base to fix the assembly of slab and distance piece firmly to the workbench. This system has the disadvantage of employing a template follower or tracer which leads to imperfections in the cutting or machining due to play in the follower.

U.S. Pat. No. 5,871,313 issued to Nenadic discloses a cutting assembly and an apparatus for self-aligned chamfering of a workpiece. The apparatus includes a mechanism for releasably securing the workpiece in preparation for a chamfering thereof, a cutting assembly, and a mechanism for moving the cutting assembly proximate the securing mechanism between a first position and a second position, wherein the cutting assembly traverses along an edge portion of the workpiece to be chamfered. This assembly is useful only for the finishing of an edge of the workpiece. It is not capable of cutting the workpiece to a desired shape.

U.S. Pat. No. 6,006,735 issued to Schlough et al. discloses an automated stone cutting system which employs a microprocessor programmed to drive a stone cutting assembly mounted on a cross travel assembly which in turn is mounted on a gantry assembly. A laser assembly is employed to provide a visual indicator to the operator as to the position of the cross travel assembly. To effectuate a preprogrammed edge configuration, the operator must first select a particular preprogrammed edge configuration from the memory and thereafter follow a series of instructional prompts on the screen to carry out the desired stoneworking operation. This type of device requires a highly skilled operator and repositioning of the cutting assembly at the start of each new piece by the operator.

SUMMARY OF THE INVENTION

The present invention provides a system for cutting and machining stone utilizing computer numerically controlled (CNC) machines whereby a plurality of pieces may be cut from a single large piece of stone or a plurality of stone slabs without repositioning and realigning the cutting device for each new piece.

Accordingly, it is a primary objective of the instant invention to provide a system for the positioning of stone slabs to be cut on a work surface and establish definite reference coordinates so that repeated operations may be performed without relocating or redefining reference coordinates.

It is a further objective of the instant invention to provide a system which permits the establishment of multiple reference coordinates on a single piece of stone so as to allow the production of multiple and different finished pieces without repositioning the stone.

It is yet another objective of the instant invention to quickly establish the position of the stone to be cut with respect to known positions on the work table so that the position of the stone need not be measured and reestablished each time a new stone is placed onto the work table.

Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view of a stone fabrication system employing the positioning device.

FIG. 2 is a side elevational view of the positioning device.

FIG. 3 is a front perspective view of the positioning deice.

FIG. 4 is a bottom view of the positioning device.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 shown is an automated stone cutting system constructed in accordance with a preferred, albeit non-limiting, embodiment of the present invention. The automated system includes a worktable 12 for restraining the stone article. Securing and supporting means 14, preferably vacuum pods, are used to hold the stone or workpiece 11 onto the worktable. Other well known supports may also be utilized. Blocking and clamping devices 16 are employed to position the workpiece on the worktable. The blocking and clamping devices have apertures in the bottom surface which engage dowel pins or other devices located at specific predefined locations on the worktable. The dimensions of the blocking and clamping devices are known so that once the stone or workpiece is abutted against the device the position of the workpiece with respect to the worktable can be established.

Turning now to FIG. 2 the blocking and clamping device 16 is shown in greater detail. A top surface 18 comprises a blocking surface 20. The blocking surface 20 is formed as a removable element which is made from a material that is softer than the stone or workpiece. This prevents the blocking surface from damaging the stone. Also, since the blocking surface is formed from a softer material it is subject to wear by the stone. In order to compensate for this, the surface 20 is removable and replaceable thereby providing a completely new surface to prevent any misalignment due to a worn surface.

On the opposite side of the device 16 is the clamping surface 22. This comprises a base 24, a stop 26, and a clamp 28. The stone is placed onto the base 24 and abutted against the stop 26 and clamped in position by clamp 28. The base 24, stop 26, and clamp 28 are also formed of a softer material and are replaceable, similar to surface 20. Once again the dimensions of the device 16 are known so that the position of the edge of the stone which abuts the stop 26 with respect to the work table is also known. A plurality of these blocking and clamping devices are employed to properly locate the stone with respect to the work table. Normally 12 of these devices are employed.

Turning now to FIG. 3 it can been seen that the device 16 has a top surface 18, a bottom surface 30, a left side surface 32, a right side surface 34, a front surface 36, and a rear surface, opposite the front surface. On the bottom surface are apertures 38 into which pins or other alignment devices mounted on the work table can be inserted. Once the device engages specific pins or alignment devices the exact location of the device 16 with respect to the work table is established. The positions of the blocking and clamping surfaces with respect to the work table are also then known.

The operator can now program into the CAD-CAM system the exact location of the workpiece. The software of the CAD-CAM system is now able to program the cutting or machining assembly to allow the production of multiple pieces at one time without the repositioning of the workpiece or realignment of the cutting assembly. In this way the set-up time for cutting multiple pieces from a single workpiece is reduced by approximately 30%.

All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims. 

1. A symmetrically arranged combination blocking and clamping device useful with a table of a computer numerically controlled (CNC) system for stoneworking including at least one locating means, said blocking and clamping device in the form of a parallelepiped comprising: a bottom surface having a plurality of apertures adapted to enable positioning about at least one locating means; a top surface having a first blocking edge and a second clamping edge, including at least one means for clamping a workpiece within said top surface second clamping edge; a left side surface; a right side surface; a front surface; a rear surface; and at least one means for fixation of said device upon said table.
 2. The blocking and clamping device of claim 1 wherein said locating means comprises a dowel pin.
 3. The blocking and clamping device of claim 2 further including means for attaching said device to said table.
 4. The blocking and clamping device of claim 1 wherein said top and said bottom surface are in removable engagement with said left side surface and said right side surface.
 5. The blocking and clamping device of claim 1 wherein said first blocking edge and said second clamping edge include removable stone workpiece abutting surfaces comprising a material which has a hardness less than that of said stone workpiece.
 6. The blocking and clamping device of claim 5 further including fasteners attaching said removable abutting surface to said first blocking edge and said second clamping edge.
 7. A stone cutting system effective for mechanically delineating defined datum points in a Cartesian coordinate system by positioning at least one datum point defining means per coordinate comprising in combination: a combination blocking and clamping device; a table of a computer numerically controlled (CNC) stoneworking machine; a locating means positioned on said table; said blocking and clamping device being in the form of a parallelepiped including a bottom surface having a plurality of apertures adapted to enable positioning about said at least one locating means, a top surface having a first blocking edge and a second clamping edge, including at least one means for clamping a workpiece within said top surface second clamping edge, a left side surface, a right side surface, a front surface, a rear surface, and at least one means for fixation of said device on said table.
 8. The stone cutting system of claim 7 wherein said locating means comprises a dowel pin.
 9. The stone cutting system of claim 7 further including means for attaching said device to said table.
 10. The stone cutting system of claim 7 wherein said top and said bottom surface are in removable engagement with said left side surface and said right side surface.
 11. The stone cutting system of claim 7 wherein said first blocking edge and said second clamping edge include removable stone workpiece abutting surfaces comprising a material which has a hardness less than that of said stone workpiece.
 12. The stone cutting system of claim 11 further including fasteners attaching said removable surface to said first blocking edge and said second clamping edge.
 13. The stone cutting system of claim 7 further including means to support said workpiece on said table.
 14. The stone cutting system of claim 13 wherein said means to support said workpiece comprises vacuum pods positioned on said table.
 15. A method for mechanically delineating defined datum points in a Cartesian coordinate system by positioning at least one datum point defining means per coordinate comprising: positioning a locating means on a table of a computer numerically controlled (CNC) stoneworking machine; positioning a blocking and clamping device on said table; said blocking and clamping device being in the form of a parallelepiped including a bottom surface having a plurality of apertures enable with said locating means, a top surface having a first blocking edge and a second clamping edge, including at least one means for clamping a workpiece within said top surface second clamping edge, a left side surface, a right side surface, a front surface, a rear surface, and at least one means for fixation of said device on said table.
 16. A method for positioning a workpiece on a stone cutting machine comprising: positioning a locating means on a table of said stone cutting machine; positioning at least one blocking and clamping device on said table; said blocking and clamping device including a top surface having a first blocking edge and a second clamping edge, including means for clamping said workpiece within said top surface second clamping edge and a bottom surface having at least one aperture engaging said locating means; positioning said workpiece against either said first blocking edge or said second clamping edge of a first said device; positioning said workpiece against either said first blocking edge or said second clamping edge of a second said device; establishing datum points in a Cartesian coordinate system; providing means coupled to a processing device for receiving said datum points; and providing means relating the position of said workpiece to said established datum points; wherein establishment of said known Cartesian coordinate datum points facilitates machine setup. 